In general, this invention relates to a fast frame recorder. More particularly, this invention relates to a fast frame recorder in which a plurality of split frames recorded during a whole frame period may be displayed either simultaneously or sequentially.
Fast frame recorders are used to effect motion analysis of fast moving phenomena in slow motion. This entails the recording of a great number of images during an event at high speed and then playback of the images slowly to analyze the event in step by step progression. Applications for motion analysis include malfunctions in high speed machinery, movements of an athlete, failure of safety equipment, trajectory analysis of a rapidly moving object such as a bullet, shattering of an object and physical reactions to a tire hitting a pot hole at high speed. The fast frame recorder (motion analyzer) disclosed in commonly assigned U.S. Pat. No. 4,789,894, issued Dec. 6, 1988, inventor Cooper, includes a video camera, a variable speed magnetic tape processor and a display monitor. The camera is capable of producing signals corresponding to selected frame rates of from about 30 to about 1000 frames per second. The video is read out from the imager in block format (i.e. a plurality of lines of video simultaneously) and is recorded in sequential blocks on a plurality of longitudinal tracks on tape. The magnetic tape processing system is capable of recording at high tape speeds and playing back at a predetermined slow speed to down convert the camera signals regardless of the camera frame rate to a nominal playback frame rate of 30 frames per second. The display monitor receives the playback signal at the reduced frame rate from the magnetic tape processing system and displays the scene in question in slow motion. This system is also capable of reading out and recording a plurality of partial frames during each whole frame. This results in a partial frame rate which is greater than the whole frame rate by a factor equal to the number of partial frames read out and recorded during each whole frame period. During playback the partial frames recorded during a whole frame period are displayed on the display monitor simultaneously. In certain applications, it has been found that a viewer of several partial frames simultaneously displayed on a monitor may become confused by the plurality of images displayed.